title: Differentiating among children with PDD-NOS, ADHD, and those with a combined diagnosis on the basis of WISC-III profiles.
abstract: Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) and Attention Deficit/Hyperactivity Disorder (ADHD) have partly overlapping symptoms. It can also be debated whether a third diagnostic category exists: children with a combined diagnosis. In this study an attempt was made to distinguish among the three groups on the basis of intelligence (WISC-III) profiles. It was found that the PDD-NOS group had higher verbal and performance IQ's, as well as higher WISC-III index scores than the ADHD group. Subtests Block Design and Mazes discriminated best. It was concluded that based on intelligence scores, only PDD-NOS and ADHD emerged as distinct categories, whereas the combined diagnosis did not. Future research on the distinctiveness of these diagnostic groups, however, should include variables other than IQ.
authors.affiliation: Developmental Psychology Section, Faculty of Social Sciences, Tilburg University, LE Tilburg, The Netherlands. j.g.m.scheirs@uvt.nl
authors.forename: J G M
authors.initials: JG
authors.lastname: Scheirs
authors.forename: E A
authors.initials: EA
authors.lastname: Timmers
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000453:epidemiology; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000175:diagnosis* / Q000453:epidemiology; D015897:Comorbidity; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D009426:Netherlands; D009483:Neuropsychological Tests; D011597:Psychomotor Performance; D012720:Severity of Illness Index; D014705:Verbal Behavior